New 1,4-dihydropyridine derivatives with potent and long-lasting hypotensive effect.

In a search for new 1, 4-dihydropyridine derivatives with a long-lasting effect on the cardiovascular system, a series of piperazinylalkyl esters (I) bearing a lipophilic substituent on the 4-nitrogen of the piperazine ring was synthesized and tested for hypotensive effect in spontaneously hypertensive rats (SHR). Compounds I, especially those having a diphenylmethyl moiety on the piperazine ring, showed extremely potent and long-lasting hypotensive properties. Analogues related to I were also prepared, and the structure-activity relationships are discussed.